The present invention relates to an x-ray diagnostic apparatus in which the imaging angle with respect to a subject has a high degree of freedom and which is suitable for inspecting a circulatory organ.
A conventional X-ray image diagnostic apparatus, particularly a circulatory organ X-ray image diagnostic apparatus that can be used during operation using a catheter or the like, is elaborated in various manners to ensure a sufficiently large operation space for the operator while increasing the degree of freedom of the imaging posture with respect to the subject. For example, a C arm is supported to be rotatable about three orthogonal rotating shafts and slidable along rails set on the ceiling or floor surface.
FIG. 1 is a perspective view of the gantry of a conventional X-ray diagnostic apparatus. An X-ray tube 150 and an X-ray detection system are supported by a C-shaped (or U-shaped) arm 152 to oppose each other through a bed 156. The arm 152 can slide along an arm holder 153 (arrow A). The arm holder 153 is tiltably held by a holder pillar 154 (arrow B). The holder pillar 154 is rotatably attached to a ceiling base 157 (arrow C). The ceiling base 157 can slide on the ceiling along rails (arrows D and E). These composite motions A to F increase the degree of freedom of the postures of the X-ray tube 150 and the X-ray detection system with respect to a subject P. The mainstream X-ray detection system is a combination of an image intensifier (I.I.) 151 and TV camera 155. A moving mechanism is provided to move the X-ray detection system close to/away from the subject P (arrow F). A o rotating mechanism is provided in order to mechanically rotate the TV camera 155 by an angle corresponding to a rotation C of the arm 152, so that the longitudinal direction of the subject P and the vertical direction of the display screen coincide with each other.
The I.I. 151 and TV camera 155 are heavy and large in size. Accordingly, the gantry becomes large in size. In recent years, a lightweight, compact planar type X-ray detector has been developed to replace the X-ray detection system comprised of the I.I. 151 and TV camera 155. This planar type X-ray detection system is comprised of a phosphor film and a solid-state detection element array arranged behind the phosphor film, converting optical signals into electrical signals. The system may be comprised of a solid-state detection element array directly converting X-ray signals into electrical signals. The solid-state detection element array is comprised of a plurality of photoelectric conversion elements, a plurality of charge storing diodes for storing charges generated by the photoelectric conversion elements, and a plurality of charge read field effect transistors (FETs). X-rays are converted into light by the phosphor film. Charges in an amount corresponding to the intensity of the light are generated by the photoelectric conversion elements. The charges are stored in the charge storing diodes and are read out as imaging signals through the FETs.
The closer the planar type X-ray detector is to the subject P, the higher the image quality. The planar type X-ray detector has a rectangular shape, and depending on its posture, its corner may abut against the subject P. In this case, the planar type X-ray detector cannot be moved further closer to the subject P.
It is an object of the present invention to provide an X-ray diagnostic apparatus in which a planar type X-ray detector can be moved very close to the subject.
In order to achieve the above object, according to the present invention, there is provided an X-ray diagnostic apparatus comprising: an X-ray tube configured to irradiate a subject with X-rays; a rectangular planar type X-ray detector formed by arraying a plurality of solid-state detection elements; a supporting mechanism configured to support the X-ray tube and the planar type X-ray detector in arbitrary postures with respect to the subject; and a suspending mechanism configured to suspend the planar type X-ray detector from the supporting mechanism, the suspending mechanism having a rotating mechanism for rotating the planar type X-ray detector through an arbitrary angle about a central path of the X-rays. When necessary, the planar type X-ray detector can be rotated so as to be very close to the subject. When necessary, the planar type X-ray detector is rotated, so that the longitudinal direction of the subject on the image and the vertical direction of the screen can coincide with each other.
There is also provided an X-ray diagnostic apparatus comprising: an X-ray tube configured to irradiate a subject with X-rays; a rectangular planar type X-ray detector formed by arraying a plurality of solid-state detection elements; a supporting mechanism configured to support the X-ray tube and the planar type X-ray detector in arbitrary postures with respect to the subject; and a suspending mechanism configured to suspend the planar type X-ray detector from the supporting mechanism, the suspending mechanism having a tilt mechanism for tilting the planar type X-ray detector by an arbitrary angle about a central path of the X-rays. When necessary, the planar type X-ray detector can be tilted so as to be very close to the subject.
There is also provided an X-ray diagnostic apparatus comprising: an X-ray tube configured to irradiate a subject with X-rays; a rectangular planar type X-ray detector formed by arraying a plurality of solid-state detection elements; a supporting mechanism configured to support the X-ray tube and the planar type X-ray detector in arbitrary postures with respect to the subject; and a suspending mechanism configured to suspend the planar type X-ray detector from the supporting mechanism, the suspending mechanism having a mechanism for moving the planar type X-ray detector close to/away from the subject. When necessary, the planar type X-ray detector can be moved close to/away from the subject so as to be very close to the subject.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.